How To Measure Floor Vent Size

Pull the vent forward and out of the opening.

How to measure floor vent size.

Take out the existing floor register and measure the length width of the opening in inches all registers will be listed in inches. Note if the register or grille you are replacing is for a wall ceiling or floor. If your duct work opening in the floor is 4 x 10 you ll need to purchase a 4 10 floor register. This means that floor registers will often be smaller number first like 4 10 or 4 12.

However the overall size of the opening must be considered. For example a 4 x 10 flush mount wood register has an overall size of 6 x 12. For sizing please use the duct size and reference the overall frame size for installation. For floor registers they follow the same rules as return grilles where you state the dimension parallel to the louvers first.

How to measure and replace a floor register. Measure the opening in your floor wall or ceiling. Length in inches by height in inches this is your duct opening size. Most vent faceplates are large enough to support the register and cover the entire hole.

Locate the register or grille you are replacing and note if it is for a wall ceiling or floor. If your hole measures 3 7 8 x 9 7 8 you should be able to use a 4 x 10 floor register depending on the style. The width and length of your opening should match the duct opening sizes. A register is measured by the size of its louvers which is the bottom of the register that fits into the ventilation duct.

Measure the size of the air duct opening. The length l is always expressed first followed by the height h dimension. Remove the screws that hold the vent in place. Then measure the length and width of the air duct opening.

Remove screws holding the vent in place. Many of our vent grilles include directional patterns so it is crucial to provide both dimensions in their respective order. Measure the duct opening in your floor wall or ceiling.